France's conservative government has unveiled new counter-terrorism measures to punish those who visit extremist websites or travel to weapons-training camps abroad, in the wake of the killings by a suspected Islamist extremist in southern France last month.

The measures now go to parliament, where they may face resistance from the Socialists, who say France's legal arsenal against terrorism is already strong enough and that the proposal is a campaign ploy to boost President Nicolas Sarkozy's chances of winning a second term.

Sarkozy's cabinet gave its go-ahead to measures that would make it illegal to travel abroad to "indoctrination and weapons-training camps for terrorist ends" or to regularly visit websites that incite or praise deadly terrorism.

Sarkozy's government insists the measures are needed to fight the relatively new phenomenon of "lone wolf" terrorism by extremists who self-radicalise online via jihadist websites, and are hard for authorities to track.

Another proposal would make it possible to use anti-terror laws to prosecute those seeking to recruit terrorists, even if their recruiting efforts fail.

The measures come amid the hyper-charged political atmosphere ahead of France's presidential and legislative elections in the coming weeks. Even the proposal's proponents admit they may not be taken up before elections reshape the National Assembly in June.

The Socialists – who could see gains in the elections – oppose the measure, arguing that France just needs to apply its counter-terrorism laws better. "We would have liked to have passed these measures before the presidential election," said government spokeswoman Valerie Pecresse of the two-round election on 22 April and 6 May.

Sarkozy first laid out such proposals after the gunman Mohamed Merah killed three paratroopers, a rabbi and three Jewish children in three shootings over eight days in the southern cities of Toulouse and Montauban in March.